Ergot

Ergot, caused by the fungus Claviceps purpurea, is a disease of cereal crops such as rye and grasses. The disease causes reduced yield and quality of grains and hay and also causes a livestock disease called ergotism, if infected grains or hay are fed.

The disease cycle of the ergot fungus was first described in the 1800s, but the connection with ergot and epidemics among people and animals was known several hundred years earlier.

Ergot's medicinal applications and animal poisoning properties first called attention to this plant disease.

Human poisoning was common in Europe in the Middle Ages when ergoty rye bread was often consumed.

Many ergot alkaloids have a poisonous effect on the central nervous system, interfering heavily with neurotransmitter function.

Among those who studied ergot and its derivatives was the Swiss chemist Albert Hofman whose experiments let to the discovery of LSD, an ergot derivative that strongly interferes with the neurotransmitter serotonin.